Liquid polyurethane foam mixtures are conventionally molded within a mold whose mold cavity is coated with a release agent in order to prevent the polyurethane foam from bonding to the mold cavity during the polymerization that takes place. Conventional release agents of this type include dispersions or emulsions of fats, waxes, soaps, greases, or oils etc. that are interposed between the mold surface and the liquid foam mixture within the mold cavity to prevent bonding of the polyurethane foam to the mold. These release agents conventionally include at least some water in the dispersion or emulsion as disclosed by U.S. Pat. Nos. 3,474,166 Babcock; 3,823,023 Duggins et al; 4,038,088 White et al; 4,131,662 Cekoric et al; 4,169,172 Bethe; 4,473,403 Wesala; 4,491,607 Wesala; 4,609,511 Fischer et al; and 4,783,296 Fischer et al.
Since any water in such release agents prevents the polyol/isocyanate reaction of the polyurethane liquid foam mixture from proceeding, it is conventional to fully dry the release agents on the mold cavity surfaces prior to introduction of the polyurethane foam liquid mixture. Such drying necessarily increases the cost and increases the cycle time of the molding process. Also, in order to perform the drying, it is conventional for the release agent to include a solvent that affects the environment upon passage to the atmosphere.
When open cell soft polyurethane foam is molded, the polyol/isocyanate reaction proceeds sufficiently so that the gas generated bursts the bubbles that are formed during the foaming process. Molds in which this molding is performed must be provided with vents for such gas to escape in order to prevent a pressure buildup that adversely affects the complete filling of the mold and uniformity of the resultant molded foam article.
Other release agents, etc. encountered during the investigation conducted for the present invention are disclosed by U.S. Pat. Nos. 3,468,989 McMillan; 3,519,444 Brown et al; and 4,690,788 Yada et al.